/**
 * 
 */
package slhs.tempo.TableAnalyzer;

/*
 * Copyright (C) 2001-2003 Colin Bell colbell@users.sourceforge.net
 * 
 * This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General
 * Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 * 
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
import java.awt.Toolkit;

import javax.swing.JTextField;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
import javax.swing.text.PlainDocument;

/**
 * This class is a <CODE>TextField</CODE> that only allows integer values to be entered into it.
 * 
 * @author <A HREF="mailto:colbell@users.sourceforge.net">Colin Bell</A>
 */
public class IntegerField extends JTextField {
    /**
     * Default ctor.
     */
    public IntegerField() {
	super();
    }

    /**
     * Ctor specifying the field width.
     * 
     * @param cols
     *            Number of columns.
     */
    public IntegerField(int cols) {
	super(cols);
    }

    /**
     * Retrieve the contents of this field as an <TT>int</TT>.
     * 
     * @return the contents of this field as an <TT>int</TT>.
     */
    public int getInt() {
	final String text = getText();
	if (text == null || text.length() == 0) {
	    return 0;
	}
	return Integer.parseInt(text);
    }

    /**
     * Set the contents of this field to the passed <TT>int</TT>.
     * 
     * @param value
     *            The new value for this field.
     */
    public void setInt(int value) {
	setText(String.valueOf(value));
    }

    /**
     * Create a new document model for this control that only accepts integral values.
     * 
     * @return The new document model.
     */
    @Override
    protected Document createDefaultModel() {
	return new IntegerDocument();
    }

    /**
     * This document only allows integral values to be added to it.
     */
    static class IntegerDocument extends PlainDocument {
	@Override
	public void insertString(int offs, String str, AttributeSet a) throws BadLocationException {
	    if (str != null) {
		try {
		    Integer.decode(str);
		    super.insertString(offs, str, a);
		} catch (NumberFormatException ex) {
		    Toolkit.getDefaultToolkit().beep();
		}
	    }
	}
    }
}
